Chinch Bugs

Chinch Bugs

chinch bugs ottawaThree species of chinch bug commonly invade turf grass in North America. Only hairy chinch bug (blissus leucopterus hirtus) occurs in Canada and is found from Ontario eastward. The chinch bug is a true bug, meaning it is a member of the order Hemiptera. Bugs are characterized by half wings, piercing-sucking mouth parts and a three stage life cycle (eggs-nymphs-adults).

Life Cycle:
Adult chinch bugs overwinter in protected places in and around turf grass. When temperatures reach 7 degrees C in spring they come out of hibernation and mate. Egg-laying begins 2 weeks later. Eggs are laid in leaf sheaths and on roots of host grasses. A single female can lay up to 20 eggs per day for 3 weeks or longer. Time to hatching varies between one month in early spring and one week in summer. Peak populations of eggs occur, when white clover is in early bloom, usually mid-June. When the eggs hatch, a nymph is released. Nymphs are incompletely formed individuals feeding immediately. Nymphs go thru five developmental stages or instars. The exoskeleton is shed at the completion of each instar by a process of molting. Successive nymphs are progressively more mobile but do not fly. It takes 4 to 6 weeks to reach the adult stage, the shorter periods occurring when temperatures are above average. In our region, adults appear in early to mid-August. In late summer and fall adults seek hibernation sites including in damaged turf with sufficient grass to supply shelter and food; in tall grass, plant debris and around foundations.

Appearance of Chinch Bug:
The adult chinch bug is only 3 to 4 mm. long. The eggs are less than 1mm. long and are white turn yellow and finally orange just before hatching. The first nymphs are about 1mm. and are bright red with a white band across their middle. The red changes to orange, orange to brown and black as the nymphs progress thru the 5 instars. Adults are black with shiny white wings. There is a distinctive black spot near the margin of each forewing and a black line extending diagonally toward the head.

Appearance of Grass Damaged by Chinch Bugs:
Expanding patches of yellowing, then dead grass in July and August. Chinch bugs feed by inserting needle-like mouth parts into crowns and stems of grasses and sucking out plant juices. At the same time they inject a toxic saliva into the plants which disrupts the water-conduction system, causing the plant to wilt and die. Their feeding pattern results in circular patches of damaged grass that turns yellow then brown as it dies. In the yellow stage the grass superficially resembles grass that is drought stressed. As the grass dies the chinch bugs work outward from the center of infestation destroying a larger area as they advance. Affected areas appear as scattered patches with a severe infestation they can coalesce into larger patches. Damage can be described as small fist sized sunken areas; the dead grass does not pull up easily which distinguishes it from other types of damage. Obvious damage usually coincides with periods of hot dry weather in July and August and occurs first in the most drought stressed regions of the lawn such as on slopes and at edges. This damage can be confused with drought stress, sunscald, summer dormancy, dog urine patches, spilled mower gas, other pests and diseases. Conversely, mid-summer semi-dormancy can mask the symptoms.

Control and Treatment of Chinch Bug:
Beneficial nematodes are tiny microscopic roundworms or threadworms (‘nema’ is Greek for thread)that are very important soil organisms. Some types of nematodes attack plants, some attack insects but most are involved in the normal decomposition processes in the soil. The beneficial, entomopathogenic (insect attacking) nematodes attack 400 pest insect species. They infect their host with particular types of bacteria and these bacteria kill the host quickly and initiate its decomposition. The nematodes feed on the decomposing host. Different nematodes species carry different bacteria and behave differently so it is important to match the nematode species with the pest species. Strains have been selected and have proved very effective for control of white grubs (European chafer, Japanese beetle and June beetle larvae, fungus gnats, onion maggots, cutworms and sod webworms), chinch bugs (common, hairy and southern chinch bugs), ants(attacks and kills young ant larvae in nests and repels adult ants from building new nests) and leatherjackets(European crane fly larvae, fungus gnats and other fly larvae). Call Harmony Gardens Landscaping to have an application of specific nematodes to control chinch bug this August.

A good horticultural program with thatch reduction thru dethatching, core aeration and proper fertilization will go a long way to preventing problems with chinch bugs. Research has also shown that over-seeding with grass that contains endophytes offers some resistance to chinch bug feeding.

Contact Harmony Gardens Landscaping Inc. for a professional consultation to assess your lawn problems; for specific nematode applications as treatment for an infestation or for preventive control measures; and for appropriate individualized lawn care programs.